U.S. patent application number 09/860552 was filed with the patent office on 2002-01-17 for ink replenishing system and method for ink jet printing apparatus.
Invention is credited to Kawanabe, Tetsuya.
Application Number | 20020005881 09/860552 |
Document ID | / |
Family ID | 18658851 |
Filed Date | 2002-01-17 |
United States Patent
Application |
20020005881 |
Kind Code |
A1 |
Kawanabe, Tetsuya |
January 17, 2002 |
Ink replenishing system and method for ink jet printing
apparatus
Abstract
A present invention provides an ink jet printing apparatus
comprising an ink replenishing system which prevents ink leakage
when a power supply from a main power source is cut off due to a
power failure or the like while an ink reserving section of a print
head of the ink jet printing apparatus is replenished with ink. The
ink replenishing system is capable of properly managing the amount
of ink in the ink reserving section. In the ink jet printing
apparatus, when a power supply from a main power source is cut off
after the start of an ink replenishing operation, power is supplied
from a secondary power source so that ink replenishing control is
executed depending on the power state of the secondary power
source. If the ink replenishing operation has not been completed,
after the main power source is recovered, the ink replenishing
operation is performed again.
Inventors: |
Kawanabe, Tetsuya;
(Kanagawa, JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Family ID: |
18658851 |
Appl. No.: |
09/860552 |
Filed: |
May 21, 2001 |
Current U.S.
Class: |
347/85 |
Current CPC
Class: |
B41J 2/175 20130101;
B41J 2/17509 20130101 |
Class at
Publication: |
347/85 |
International
Class: |
B41J 002/175 |
Foreign Application Data
Date |
Code |
Application Number |
May 24, 2000 |
JP |
2000-153631 |
Claims
What is claimed is:
1. An ink replenishing system for an ink jet printing apparatus for
replenishing an ink reserving section of a print head with ink from
an ink replenishing section, comprising: said ink reserving section
configured so as to be connected to and separated from said ink
replenishing section via an opening formed in said ink reserving
section; and said ink replenishing section configured so as to
replenish said ink reserving section with ink by controlling
driving of an actuator, wherein when a power supply from a main
power source is cut off after the start of an ink replenishing
operation, the power supply is switched to a secondary power source
and replenishing control is executed depending on a power state of
said secondary power source.
2. An ink replenishing system for an ink jet printing apparatus as
claimed in claim 1, wherein when the power state of said secondary
power source is such that the second power source has sufficient
power to complete the ink replenishing operation, the ink
replenishing operation is controlled so as to complete the
connection operation, the ink replenishing operation, and the
separation operation.
3. An ink replenishing system for an ink jet printing apparatus as
claimed in claim 1, wherein when the power state of said secondary
power source is such that it does not have sufficient power to
complete said ink replenishing operation, said ink replenishing
operation is suspended and at least the separation operation is
completed, and the amount of ink supplied before the ink
replenishing operation is suspended is stored, and wherein when the
main power supply is subsequently recovered, the ink replenishing
operation is performed again to replenish the ink reserving section
with an amount of ink sufficient to compensate for the
shortage.
4. An ink replenishing system for an ink jet printing apparatus as
claimed in claim 1, wherein said secondary power source is
chargeable batteries.
5. An ink replenishing system for an ink jet printing apparatus as
claimed in claim 1, wherein a secondary-power-source voltage
detector is provided for detecting a voltage at said secondary
power source in order to detect the power state of said secondary
power source, and a warning is issued if said detector detects a
predetermined voltage or less.
6. An ink replenishing method for an ink jet printing apparatus for
replenishing an ink reserving section of a print head with ink from
an ink replenishing section, comprising steps of: connecting said
ink reserving section to said ink replenishing section via an
opening formed in said ink reserving section; replenishing said ink
reserving section with ink from said ink replenishing section by
controlling driving of an actuator; and separating said ink
reserving section from said ink replenishing section, wherein when
a power supply from a main power source is cut off after the start
of an ink replenishing operation, the power supply is switched to a
secondary power source and replenishing control is executed
depending on a power state of said secondary power source.
7. An ink replenishing method for an ink jet printing apparatus as
claimed in claim 6, wherein when the power state of said secondary
power source is such that the second power source has sufficient
power to complete the ink replenishing operation, the ink
replenishing operation is controlled so as to complete the
connection step, the ink replenishing step, and the separation
step.
8. An ink replenishing method for an ink jet printing apparatus as
claimed in claim 6, wherein when the power state of said secondary
power source is such that it does not have sufficient power to
complete said ink replenishing operation, said ink replenishing
operation is suspended and at least the separation operation is
completed, and the amount of ink supplied before the ink
replenishing operation is suspended is stored, and wherein when the
main power supply is subsequently recovered, the ink replenishing
operation is performed again to replenish the ink reserving section
with an amount of ink sufficient to compensate for the
shortage.
9. An ink replenishing method for an ink jet printing apparatus as
claimed in claim 6, wherein said secondary power source is
chargeable batteries.
10. An ink replenishing method for an ink jet printing apparatus as
claimed in claim 6, wherein a secondary-power-source voltage
detector is provided for detecting a voltage at said secondary
power source in order to detect the power state of said secondary
power source, and a warning is issued if said detector detects a
predetermined voltage or less.
Description
BACKGROUND OF THE INVENTION
[0001] This application is based on Patent Application No.
2000-153631 filed May 24, 2000 in Japan, the content of which is
incorporated hereinto by reference.
[0002] 1Field of the Invention
[0003] The present invention relates to a printing apparatus for
forming images on printing medium, and in particular, to an ink
replenishing system for replenishing an ink reserving section of a
print head of an ink jet printing apparatus with ink.
[0004] 2. Description of the Related Art
[0005] In the field of image printing apparatuses, colors, printing
speed, definition, and image quality have lately been improved to
enable the output of a large amount of high-grade images that
appear like photographs. In particular, an increasing number of
fast printing apparatuses that act as shared equipment through
network connections have been demanded.
[0006] In these circumstances, ink jet printing apparatuses are
required to increase the amount of ink stored for printing to
reduce the frequency with which ink must be supplied, in order to
reduce the running costs of the equipment and to enable easy
maintenance. To meet such requirements, a method has been proposed
which is used in a system for replenishing an ink reserving section
of a print head of an ink jet printing apparatus with ink from an
ink replenishing section, to move the ink reserving section to the
ink replenishing section and connect the ink replenishing section
to the ink reserving section via an opening formed therein to
replenish the ink reserving section with ink.
[0007] With this conventional method, to move a carriage having the
ink reserving section mounted therein to the ink replenishing
section of the print head in order to replenish the ink reserving
section with ink or to replenish the ink reserving section with ink
from the ink replenishing section after the ink replenishing
section has been connected to the ink reserving section via a pipe,
it is necessary to control driving of an actuator for driving the
carriage, a supply valve, a pressurizing pump, or the like.
[0008] After, however, an ink replenishing operation has been
started, if a power failure or accidental cutting of a power supply
line occurs during ink replenishing operation control, the
operation of the actuator is immediately stopped to cause the
carriage movement as well as the valve and the pump to be
inappropriately controlled, resulting in ink leakage from
connections or the like. Additionally, if a main power supply is
cut off during the ink replenishment operation, the amount of ink
already supplied is disadvantageously unknown, thereby hindering
the amount of ink in the ink reserving section from being properly
managed after the main power supply has been recovered.
SUMMARY OF THE INVENTION
[0009] To solve these problems, the present invention provides an
ink replenishing system for replenishing an ink reserving section
of a print head of an ink jet printing apparatus with ink from an
ink replenishing section. In the ink replenishing system, the ink
reserving section is configured so as to be connected to and
separated from the ink replenishing section via an opening formed
in the ink reserving section. An object of the present invention is
to provide an ink jet printing apparatus comprising an ink
replenishing system which is configured so as to replenish the ink
reserving section with ink by controlling the driving of an
actuator and which switches, when a power supply from a main power
source is cut off after the start of an ink replenishing operation,
to a power supply by a secondary power source and controls the
replenishing operation depending on a power state of the secondary
power source.
[0010] Further, when the power state of the secondary power source
is such that it has sufficient power to complete the ink
replenishing operation, the replenishing operation is controlled so
as to complete the connection operation, the ink replenishing
operation, and the separation operation. When the power state of
the secondary power source is such that it does not have sufficient
power to complete the ink replenishing operation, the ink
replenishing operation is suspended and at least the separation
operation is completed. Furthermore, the amount of ink supplied
before the ink replenishing operation is suspended is stored, and
when the main power supply is subsequently recovered, the ink
replenishing operation is performed again to replenish the ink
reserving section with an amount of ink sufficient to compensate
for the shortage. It is another object of the present invention to
provide an ink jet printing apparatus comprising an ink
replenishing system configured as described above.
[0011] The above and other objects, features and advantages of the
present invention will become more apparent from the following
description of embodiments thereof taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a view showing the configuration of a printing
apparatus to which the present invention is applicable;
[0013] FIG. 2 is a view showing an ink replenishing system of a
first embodiment, wherein an ink reserving section separates from
an ink replenishing section;
[0014] FIG. 3 is a view showing the ink replenishing system of the
first embodiment, wherein an ink reserving section connects to an
ink replenishing section;
[0015] FIG. 4 is a flow chart showing ink replenishing operation
control of the first embodiment;
[0016] FIG. 5 is a flow chart showing the replenishing process from
FIG. 4 in detail;
[0017] FIG. 6 is a flow chart showing emergent replenishing
operation control of the first embodiment;
[0018] FIG. 7 is a view showing an ink replenishing system of a
second embodiment, wherein an ink reserving section separates from
an ink replenishing section; and
[0019] FIG. 8 is a view showing the ink replenishing system of the
second embodiment, wherein an ink reserving section connects to an
ink replenishing section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] FIG. 1 is a view useful in explaining a configuration of a
printing apparatus to which the present invention is applicable. A
control circuit (CONT) 1 controls the entire printing apparatus of
the present invention and, although not shown, comprises a CPU, a
RAM, an NVRAM (non-volatile memory), a ROM, an I/O port, a DMA
controller, a programmable timer, an interruption controller, an
actuator driving circuit, an interface control circuit, and others.
A printing mechanism (PRT) 2 comprises a print head, a carriage, a
printing medium feeding mechanism, an ink replenishing system, and
others.
[0021] The control circuit 1 operates in accordance with programs
previously stored in the ROM to control the entire operation of the
printing apparatus by executing printing output in accordance with
demands from a host computer or the like connected thereto through
an interface as required and controlling an ink replenishing
operation as required.
[0022] Power supply devices are denoted by reference numerals 3 to
8. Reference numeral 3 denotes a power supply line to the control
circuit 1. Reference numeral 5 denotes a main power source (PWR1)
for normally supplying power to the printing apparatus, reference
numeral 6 denotes a secondary power source (PWR2) composed of
batteries, for supplying power in an emergency, and reference
numeral 4 denotes a switcher. Reference numeral 7 denotes a power
source switching control means (PSC) for monitoring the voltage at
the main power source 5 to switch, on detecting a decrease in the
voltage at the main power source 5 which is caused by a power
failure or the like, the switcher 4 to the secondary power source 6
side, while transmitting a switching signal to inform the control
circuit 1 of this decrease by means of interruption or the like.
Reference numeral 8 denotes a secondary-power-source voltage
detector (PDT) for monitoring the voltage at the secondary power
source 6 and transmitting, on detecting a voltage equal to or lower
than a predetermined value, a detection signal to inform the
control circuit 1 of this low voltage by means of interruption. The
secondary power source 6 may be composed of chargeable batteries;
in this case, a charge control circuit may be added thereto.
[0023] A first embodiment of the ink replenishing system of the
present invention will be described with reference to FIGS. 2 to 6.
In FIG. 2, reference numeral 10 denotes an ink reserving section
for replenishing the print head with ink, the ink reserving section
being provided on the carriage (not shown) together with the print
head. The ink reserving section 10 has a first liquid chamber 11
and a second liquid chamber 12 which are in communication with each
other via a communication passage 15. The first liquid chamber 11
is filled with a liquid absorbent 13 and has a supply passage 16 in
communication with the print head (not shown). The ink stored in
the second liquid chamber 12 gradually permeates through the liquid
absorbent 13 through the communication passage 15. The ink
permeating through the liquid absorbent 13 passes through the
supply passage 16 to replenish the print head with an amount of ink
required for printing (the ink is supplied in the direction of an
arrow A).
[0024] The liquid absorbent 13 is composed of a porous material,
for example, spongy plastics, foam rubber, or a fibrous material,
and its pores forms capillaries for a liquid. Reference 14 denotes
an opening formed in the second liquid chamber and connected,
during an ink replenishing operation, to a supply pipe 23 of an ink
replenishing section 20, described later.
[0025] The ink replenishing section 20 is fixed to a main body side
of the ink jet printing apparatus. In this embodiment, the ink
replenishing section 20 is of a type that supplies a liquid
utilizing a difference in the water head. It comprises an ink
storage chamber 21, a supply valve 22, and a supply pipe 23 that
can be connected to the opening 14 in the second liquid chamber 12
during the ink replenishing operation. The supply valve 22 is
configured to have its driving controlled by an actuator (not
shown) so as to be opened and closed as required.
[0026] During the ink replenishing operation, the driving of the
actuator (not shown) for scanning the carriage during a printing
operation is controlled to move the carriage having the ink
reserving section 10 mounted thereon, in the direction of the arrow
B in FIG. 2 from the position shown in FIG. 2 to the position shown
in FIG. 3, ("connection operation"). At this time, the ink
reserving section 10 is stopped at a position into which it does
not advance during a normal printing operation, so as not to effect
unwanted load motion on the carriage during the printing
operation.
[0027] As shown in FIG. 3, the second liquid chamber 12 can be
replenished with a desired amount of ink from the ink storage
chamber 21 by opening the supply valve 22 with the supply pipe 23
connected to the opening 14. Once the ink replenishing operation is
completed, the supply valve 22 is closed, the carriage having the
ink reserving section 10 mounted thereon is moved, by controlling
the driving of the actuator (not shown), in the direction opposite
to that during the connection operation so as to return to its
initial state as shown FIG. 2 ("separation operation").
[0028] FIGS. 4 and 5 are flow charts useful in explaining the ink
replenishing operation control performed while power is being
supplied by the main power source 5. This control is programmed in
the ROM in the control circuit 1 in advance. The normal control
(performed while power is being supplied by the main power source
5) of the ink replenishing operation starts when, for example, a
detection signal sensing that the level in the second liquid
chamber 12 has decreased down to a predetermined value is input to
the control circuit 1.
[0029] The power state of the secondary power source 6 is always
monitored by the control circuit 1 utilizing a detection signal
from the secondary power source voltage detector 8. Accordingly,
when the secondary power source voltage detector 7 detects a state
where the voltage at the secondary power source 6 is so low that an
emergency replenishing operation cannot substantially be achieved
(at least the operation of closing the supply valve 22 and
separating cannot be performed), the ink replenishing operation is
disabled beforehand and this is warned to an operator beforehand in
such a manner as described later.
[0030] As shown in FIG. 4, once the ink replenishing operation is
started, the above described connection operation is performed at
step S1, that is, the ink reserving section 10 is moved from the
position shown in FIG. 2 to the position shown in FIG. 3. Then, at
step S2, the supply valve 22 is opened, and at step S3, the
replenishing process is executed. The replenishing process at the
step S3 is shown in FIG. 5 in detail. When the replenishing process
is started, a timer starts at step S21 to begin measuring the
amount of time spent for the replenishing operation. Subsequently,
it is determined at step S22 whether or not a switching signal
indicating that the main power source has been cut off and that the
power supply has been switched to the secondary power source has
been transmitted to the control circuit 1 by means of interruption
or the like. If the main power source 5 is being used to supply
ink, the interruption of the switching signal does not occur, so
the procedure proceeds to step S24 to calculate the amount of ink
supplied. Then, it is determined at step S25 whether or not the
replenishing operation has been completed. If the replenishing
operation has not been completed, the procedure returns to the step
S22 and if the replenishing operation has been completed, the timer
is reset at step S26. Referring back to FIG. 4, the procedure
proceeds to step S4 to close the supply valve 22. Then, at step S5,
a separation operation is preformed so as to establish the initial
positional relationship, that is, the one shown in FIG. 2, thereby
finishing the ink replenishing operation control.
[0031] FIG. 6 is a flow chart useful in explaining the emergency
replenishing operation control started when, after the start of the
ink replenishing operation, the power supply from the main power
source 5 stops due to a power failure or the like to cause the
secondary power source 6 to start a power supply, while the power
source switching control circuit 7 transmits a switching signal to
inform the control circuit 1 of this switching by means of the
interruption means. When the power supply from the main power
source 5 stops before the start of the ink replenishing operation,
the entire apparatus is stopped without switching to the secondary
power source 6.
[0032] Various points of time when the secondary-power-source
switching signal is transmitted to the control circuit 1 after the
start of the ink replenishing operation are assumed. A description
will be given of a case where while a normal replenishing process
(step S3 in FIG. 4) is being executed under the ink replenishing
operation control, the switching signal is provided to the control
circuit 1 to inform it that the power source has been switched.
[0033] When the control circuit 1 is informed of the switching of
the power source by means of interruption, at step S31, the
operator is warned through an indicator or an alarm sound that the
power supply has been switched to the secondary power source 6.
Alternatively, if the interface connected to the printing apparatus
can communicate with it in a bidirectional manner, the operator is
warned of the switching via a host computer by, for example,
displaying a message on the computer being used by the operator.
Subsequently, at step S32, it is determined whether or not
batteries constituting the secondary power source 6 are providing
sufficient power.
[0034] If the secondary power source is, for example, nickel-metal
hydride batteries, which has sufficient power to complete the ink
replenishing operation (or the voltage at the secondary power
source is sufficiently high), a replenishing process is executed
which is substantially the same as that during the normal
operation, as shown in FIGS. 4 and 5. That is, at step S22, it is
determined whether or not the switching of the power supply to the
secondary power source 6 by means of interruption has occurred. In
this case, since such switching has occurred, the procedure
proceeds to step S23 to determine whether or not the secondary
power source is providing sufficient power. Since the power from
the secondary power source is sufficient again, the procedure
proceeds to step S24. Subsequently, as in the normal operation, the
amount of ink supplied is calculated at the step S24, and it is
then determined at step S25 whether or not the replenishing
operation has been completed. If the replenishing operation has not
been completed, the procedure returns to the step S22. Once the
replenishing operation is completed, the timer is reset at step
S26. Furthermore, at the step S4 in FIG. 4, the supply value 22 is
closed, and at the step S5, the separation operation is performed
to end the ink replenishing operation. After the ink replenishing
operation has been finished, in contrast to the control provided
during the normal operation, such control is provided that an
operation such as printing is prohibited to restrain the
consumption of power from the secondary power source until the main
power source 5 is recovered.
[0035] Further, if the secondary power source is, for example,
batteries, which have power insufficient to complete the ink
replenishing operation but at least sufficient to close the supply
valve 22 for the separation operation, then the operator is warned
at step S31, and it is determined at step S32 that the secondary
power source is not providing sufficient power, so that the
procedure proceeds to step S33. At the step S33, whether or not the
supply valve 22 is open is determined. In this case, since the ink
replenishing process is being executed, the supply valve 22 is open
and the procedure proceeds to step S34 to immediately close the
supply valve 22. Then, at step S35, the timer is stopped, and at
step S36, the separation operation is completed. Furthermore, at
step S37, the amount of ink supplied before the supply valve 22 is
closed is calculated, and at step S38, the amount of ink supplied
is stored in the NVRAM, and the ink replenishing operation is then
finished. In this case, the operation such as printing is
prohibited until the main power source 5 is recovered as in the
above described case where the secondary power source provides
sufficient power. However, when the main power source 5 is
subsequently recovered, the ink replenishing operation is performed
again to supply an amount of ink sufficient to compensate for the
shortage, that is, the required amount of ink supplied minus the
amount of ink supplied as stored in the NVRAM.
[0036] Then, a method for calculating the amount of ink supplied to
the ink reserving section after the supply valve has been opened
and before the ink replenishing operation is suspended.
Calculations or experiments are carried out to determine in advance
the flow rate per unit time for each ink type (color type or
composition), the channel resistance factor for a supply pipe for
said each ink type, and the channel resistance factor for the
supply pipe for each ink type as obtained when the ink viscosity
changes due to a change in temperature, and the flow rate per unit
time is stored, for example, in the ROM as table data, using a
matrix of said ink type and said temperature. Then, the unit time
flow rate dependent on the type of ink to be supplied and on the
temperature during the replenishing operation is determined and
multiplied by the amount of time required for the replenishing
operation as actually measured after the supply valve 22 has been
opened and before the ink replenishing operation is suspended,
thereby making it possible to determine the amount of ink supplied
to the ink reserving section.
[0037] Further, if the secondary-power-source voltage detector 7
detects, while the emergency replenishing operation control is
being executed through the secondary power source 6, that the
voltage at the secondary power source 6 has decreased down to a
predetermined value or less, so that the ink replenishing operation
cannot be completed, that is, it is determined at the step S23 in
FIG. 5 that the power from the secondary power source is
insufficient, the procedure proceeds to the step S33 in FIG. 6 to
determine whether or not the supply valve 22 is open. In this case,
since the ink replenishing process is being executed, the supply
valve 22 is open and the procedure proceeds to the step S34 to
immediately close the supply valve 22. Then, at the step S35, the
timer is stopped, and at the step S36, the separation operation is
completed. Furthermore, at the step S37, the amount of ink supplied
before the supply valve 22 is closed is calculated, and at the step
S38, the amount of ink supplied is stored in the NVRAM, and the ink
replenishing operation is then finished. In this case, when the
main power source 5 is subsequently recovered, the ink replenishing
operation is also performed to supply an amount of ink sufficient
to compensate for the shortage, that is, the required amount of ink
supplied minus the amount of ink supplied as stored in the
NVRAM.
[0038] In the above description of the emergency replenishing
operation control with reference to FIGS. 5 and 6, the switching
signal informs the control circuit 1 of the switching of the power
source during the normal replenishing process under the ink
replenishing operation control (the power supply from the main
power source stops). The power supply from the main power source 5,
however, is not stopped only during the normal replenishing process
under the control of the ink replenishing operation control. The
emergency replenishing operation control executed in other cases
(for example, during the connection operation) have not bee
described, but it is easily understandable from FIGS. 5 and 6 and
the above description that similar control is provided in these
cases.
[0039] Next, a second embodiment of the ink replenishing system of
the present invention will be described with reference to FIGS. 7
and 8.
[0040] In FIG. 7, the ink reserving section 10 is provided on the
carrier (not shown) together with the print head as in the above
first embodiment. The ink reserving section 10 has the first liquid
chamber 11 and the second liquid chamber 12 which are in
communication with each other via the communication passage 15. The
first liquid chamber 11 is filled with the liquid absorbent 13 and
has the supply passage 16 in communication with the print head (not
shown). The ink stored in the second liquid chamber 12 gradually
permeates through the liquid absorbent 13 through the communication
passage 15. The ink permeating through the liquid absorbent 13
passes through the supply passage 16 to supply the print head with
an amount of ink required for printing (the ink is supplied in the
direction of an arrow A), as in the first embodiment.
[0041] An ink replenishing section 30 is fixed to a main body side
of the ink jet printing apparatus. Although the ink replenishing
section 30 differs from the first embodiment in that the ink is
supplied by means of a pump 32, it has an ink storage chamber 31
for storing ink and a supply pipe 33 that can be connected to the
opening 14 in the second liquid chamber 12 during the ink
replenishing operation, as in the first embodiment. The pump 32 is
configured to have its driving controlled by an actuator (not
shown) so as to suck the ink from the ink storage chamber 31 and
force it to the supply pipe 33.
[0042] During the ink replenishing operation, the carriage having
the ink reserving section 10 mounted thereon is moved in the
direction of the arrow B from its position shown in FIG. 7 and then
stopped at its position shown in FIG. 8 ("connection operation").
The operation of the pump 32 is controlled to replenish the second
liquid chamber 12 with a desired amount of ink from the ink storage
chamber 31. Once the ink replenishing operation is completed, the
pump 32 is stopped, the carriage having the ink reserving section
10 mounted thereon is moved in the direction opposite to that
during the connection operation, so as to return to its state shown
in FIG. 7 ("separation operation").
[0043] Ink replenishing operation control similar to that in the
first embodiment is executed as the emergency replenishing
operation control started when, after the start of the ink
replenishing operation control and the ink replenishing operation,
the power supply from the main power source 5 stops due to a power
failure or the like to cause the secondary power source 6 to start
a power supply, while the power source switching control circuit 7
informs the control circuit 1 of this switching by means of the
interruption means.
[0044] In the two above described embodiments, the ink replenishing
systems using the single type of ink have been described. The
present invention, however, is applicable to color printers using
inks of plural colors by providing as many ink replenishing systems
as the colors.
[0045] The present invention provides a printing apparatus
comprising an ink replenishing system moving a carriage having an
ink reserving section of a print head mounted thereon in order to
replenish the ink reserving section with ink, subsequently joining
the ink reserving section to an ink replenishing section via a
pipe, and then using an actuator to control a supply valve, a
pressurization pump, or the like to feed ink from the ink
replenishing section to the ink reserving section, wherein even if
a power failure, accidental cutting of a power supply line, or the
like occurs during an ink replenishing operation, the operation of
the actuator is prevented from being immediately stopped and a
separation operation is reliably completed by means of a secondary
power source. Consequently, the movement of the carriage can be
controlled, the valve or the pump can be prevented from being
improperly controlled, and the ink can be prevented from leaking
from connections or the like. Furthermore, if the ink replenishing
operation is stopped before completion, the ink replenishing
operation is performed again during the recovery of a main power
source to supply an amount of ink sufficient to compensate for the
shortage, thereby making it possible to properly manage the amount
of ink in the ink reserving section.
[0046] The present invention has been described in detail with
respect to preferred embodiments, and it will now be apparent from
the foregoing to those skilled in the art that changes and
modifications may be made without departing from the invention in
its broader aspect, and it is the intention, therefore, in the
apparent claims to cover all such changes and modifications as fall
within the true spirit of the invention.
* * * * *